10212111221 has 4 divisors (see below), whose sum is σ = 10997658252. Its totient is φ = 9426564192.

The previous prime is 10212111197. The next prime is 10212111269. The reversal of 10212111221 is 12211121201.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12211121201 = 89 ⋅137203609.

It can be written as a sum of positive squares in 2 ways, for example, as 1055535121 + 9156576100 = 32489^2 + 95690^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-10212111221 is a prime.

It is a super-2 number, since 2×10212111221² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 10212111196 and 10212111205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10212111271) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 392773496 + ... + 392773521.

It is an arithmetic number, because the mean of its divisors is an integer number (2749414563).

Almost surely, 2^10212111221 is an apocalyptic number.

It is an amenable number.

10212111221 is a deficient number, since it is larger than the sum of its proper divisors (785547031).

10212111221 is an equidigital number, since it uses as much as digits as its factorization.

10212111221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 785547030.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 10212111221 its reverse (12211121201), we get a palindrome (22423232422).

The spelling of 10212111221 in words is "ten billion, two hundred twelve million, one hundred eleven thousand, two hundred twenty-one".